Lift truck



Feb. 14, 1933. J. o, FERNSTROM LIFT TRUCK Filed Aug. 13, 1931 3Sheets-Sheet 1 Patented Feb. 14, 1933 PANY, OF CHICAGO,

Application filed August 13, 1931.

TBS

Arar- O, ILLINOIS, ASSIGNOR TO BARRETT-CRAVENS COM-.

ILLINOIS, A CORPORATION OE ILLINOIS LIFT TRUCK The present inventionrelates generally to lifttrucks of the type comprising a wheel supportedmain frame and a lifting frame or platform movably connected to thewheeled or mam frame. When the lifting platform is in its loweredposition frame or the truck is adapted to be backed under a platform orother support on which the load to ported has be transbeen placed, andthen by operat ing suitable lifting mechanism the lifting platform canbe raised to elevate from ported from one place to another.

the load the floor whereby it can be easily trans- More specifically,the present invention is concerned with such raising of the lifting in aplurality of lift trucks where the frame 1s accomplished steps, suchtrucks bem generally designated as multi-lift trucks.

L 1.1 or this type h mg s ave the advantage of able to raise andtransport somewhat hea 'er loads than trucks in which the lifting selevated in one operation.

Generally, however, trucks of t he multilift type are somewhat morecomplicated,

particularly as regards the liftin g mechanism and the means for holdingthe lifting frame in raised single lift type.

position, than trucks of the principal object, therefore, of the presentinvention is to provide lifting means for trucks of the multi-lift typewhlch 1s simple and sturdy and which is free f plications and which 18inexpensive facture.

rom comto manu- Briefly, the present invention contemplates a verticallymain frame hook which successively engages portions of rack means formedas nent part of the lifting frame ranged that the successively tions arebrought substantially to position to at the beginnin. present inventionswinging handle pivoted to the and operating a lifting link or differenta permaand so arengaged porthe same be engaged by the lifting hook g ofeach llfting step. The

also contemplates a simple and inexpensive rack bar or ratchet mechanismcooperating directly with n -ncs to hold the lifting frame in the twoits raised position bet een the successive lifting steps.

The present invention also con templates Serial No. ssasoi.

certain improvements in the means for releasing the lifting and holdingmechanisms to permit the lifting frame to descend, such improvementswhich will be described later in detail, being directed toward securinga simple and sturdy lift truck.

Other objects and advantages of the present invention will be apparentto those skilled in the art after aconsideration of the followingdetailed description of the pre ferred structural embodiment, taken inconjunction with the accompanying drawings in which:

Figure 1 is a vertical elevation of one form of my improved lift truck,certain parts be ing broken away in order to show the lifting andholding mechanism;

Figure 2 is a top plan view of the lift truck shown in Figure 1;

Figure 3 is a vertical elevation of a moditied form of lift truckembodying the principles of the present invention, certain parts of thetruck being broken away in order to show more clearly certain details ofthe lifting mechanism;

Figure 4 is a top plan view of the truck shown in Figure 3;

- Figure 5 is an enlarged perspective view of one of the holding rackbars utilized in the truck shown in Figure 3 to hold the lifting framein any one of its elevated positions;

Figures 6 and and plan views modified form of ing the lifting mechanismout of engagementwith the lifting frame in order to allow the latter tolower; and

Figures 8 and 9 are also fragmentary elevation and plan viewsillustrating a still further modified form of releasing mechanism forthe lifting means.

Referring now more particularly to Figure l, the reference numeral 1indicates in its entirety the main or wheeled supporting frame. The mainframe 1 includes side bars 2 connected together at their rear ends by anangle bar 3 and at their forward ends by a cross head 6. The rearmostendportions of the side bar 2 are downturned, as best shown in Figure 1,and are apertured to receive an axle shaft 7 upon which the rearsupporting wheels 8 are journaled. The forward ends of the side bars 2are connected to the cross head 6 by bolts 10 and 11.

The lifting frame is indicated in its entirety by the reference numeral15 and, like the main frame 1, consists of a pair of side bars 16connected together at their rear ends by an angle bar 18 and at theirfront ends by a T bar 19. The lifting frame 15 is pivotally connectedwith the main frame 1 so as to swing upwardly and forwardly with respectthereto. Connecting means between the main and lifting frames comprisesswinging links preferably arranged in pairs. The forward pair ofswinging links is designated by the reference numeral 21 and, as seen inFigures 1 and 2, each link 21 is pivotally mounted on the bolt 10secured to the cross head 6 and is connected by a bolt 22 to the forwardend of the side bars 16. The rear links are designated by the referencecharacter 25, each of these links being journaled on the axle shaft 7and connected together by transverse journal means 26 seated in theapex: of the angle bar 18, as clearly disclosed and claimed in PatentNo. 1,773,935, issued August 26, 1930, to Arthur M. Barret The crosshead 6 is provided with a portion 30 carrying a vertical bore in whicha. king bolt (not shown) is jounaled. The king bolt carries a pair ofsupporting and steering wheels 31 at its lower end and at its upper enda king bolt cap 33 including a pair of apertured forwardly extendinglugs 35 carrying a pivot bolt or pin 36.

The lifting mechanism for raising the lifting frame 15 includes alifting and steering handle 38 includin spaced bars 39 at its lower endpivoted On the pivot pin 36 for swinging movement in a vertical plane.The handle 38 is also operative to turn the king bolt and urge thewheels 31 to steer the truck. A curved lifting lever 40 is also pivotedon the pivot pin 36 and is formed with a loop portion 41 and a hookportion 42, the latter being adapted to be latched to the lifting handle38 by means of a dog or detent ll. By virtue of the curvature of theloop portion 41 when the handle 38 is swung vertically it serves toraise and lower the loop portion substantially vertically in the axis ofthe king bolt as more fully disclosed in the copending application ofArthur M. Barrett, Serial No. 454,26l, filed May 21, 1930. The detailsof this lifting head per se form no part of the present inven tiOn, itbeing sufiicient to note here that when the lifting handle 38 is swungrearwardly to permit the detent 4a to engage the hook portion l2 of thelifting lever 40, the latter is then latched to the lifting handle andforms a part thereof.

As a means for transmitting the vertical oscillations of the liftinghandle 38 to the lifting frame to raise the same, the present in"-vention provides a two-part lifting link 50, the upper end of whichincludes an eye 51 arranged to embrace the lifting lever H) andpivotally connected with the lower portion of the lifting link by avertical pivot bolt 53. The function of the vertical bolt 53 is toprovide for different lateral positions in which the lifting handle 38may be when it is desired to raise the lifting frame. The lower end ofthe link is formed somewhat of a hook, as indicated by the referencenumeral 55. The purpose of the hook portion 55 is to engage the liftingframe and elevate the same when the lifting handle 38 and the liftinglink 50 are oscillated.

The lifting frame 15 carries a pair of castings 57 and 58 riveted orbolted to the transverse T bar 19, the latter being welded or otherwisesecured to the side bars 16 of the lifting frame 15. A pair of plates 60and 61 are provided by the castings 57 and 58.

The plates 60 and 61 are spaced apart an amount slightly in excess ofthe lifting link 50, as best shown in Figure 2, and of lower dependingportions 60a and 61a which carry a plurality of pins 63 spaced apart inequal amounts and arranged in a generally downwardly and rearwardlyextending curve.

These pins carried by the plates 60 and 61 serve as a rack or ratchetwith which the hook 55 successively engages to raise the lifting frame,as will be described later.

The lifting platform 15 is held in any one of its raised positions bymeans of a pair of rack bars 67 and 68 having rear journal bosses 69 and70 pivotally supported by a transverse fined shaft 71 secured to themain frame 1. These rack bars 67 and 68 extend forwardly and upwardlyfrom their journal support on the fixed shaft 71 in a direction to bringthem alongside the lifting link 50, both of which are positionedapproximately in tangential relationship to the arc of movement of thelifting frame 15 about the forward pivotal support 10. The rack bars 67and 68 are positioned outside the plates 60 and 61, as shown in Figure2. A lug or plate portion is provided on each of the castings 57 and 58and are arranged outside of the rack bars 67 and 68 and the plates 60and 61, these lugs or plate portions being indicated by the referencenumerals 73 and 74:- Each of the rack or holding bars have a pair ofnotches in its lower surface, these notches being staggered with respectto each other, as shown in Figure 1. The notches in the rack bar 67 areindicated by the reference characters a and b and the notches in theother rark bar 68 are designated by the reference characters 0 and cl.

A pin is carried by the plate portions 73 and 60 formed on the castingmember 57, and a similar pin is carried by the plate portions 61 and 74formed on the other casting 58,

to lie in a position ranged that the rack bars lie above the tially tothe same position just these pins 80 and 81 being preferably arranged inalignment, as indicated in Figure 2. The plate portions and the pins areso arpins, and for this purpose the T bar 19 may be formed with a notch83 as indicated in Figure 1. The rack bar 67 overlies the pin 80 and therack bar 68 overlies the pin 81.

The operation of the lifting truck just described is substantially asfollows. When the lifting handle 38 is rocked rearwardly a sufiicientamount to cause the detent 44; to en gage the hooked end 12 of thelifting lever 40, a downward swinging movement of the lifting handle 38will exert a direct forward and upward pull on the lifting link 50, theeye member 51 thereof moving substantially vertically in a line with thesteering axis as defined by the king post. The resulting upward movementor oscillation of the lifting link 50, the lower hooked end 55 of whichengages the first pin 63 carried by the plates 60 .nd 61 on the liftingframe, raises the lifting rame through the first is step at which timepin 81 on the right lianc side of the truck ngages the notch (Z formedon the lower surace of the right hand rack bar 68. This rack artherefore holds the lifting frame in its rst elevated position. Theupward movement of the lifting frame 15 causes the second pin 63 tooccupy a position substantially the same as the position formerlyoccupied by the first pin 63 when the lifting frame was in its lowermostposition. Therefore the lifting handle 38 can be raised to cause thelifting link 50 to lower, whereby the hook 55 will be engaged ver thesecond pin 63. If the lift ing handle 38 is now given a second downvward movement the lifting link 50 will be pulled upwardly to raise thelifting platform 15 through the second step. At this time the pin 81will leave the notch (Z on the right hand rack bar 68 and will occupy aposition substantially midway between the notch (Z and the notch 0.However, the pin 80 on the left hand side of the truck and with whichthe left hand rack bar 67 cooperates will be in a position to be engagedby the notch Z) on the rack bar 67. At the end, therefore, of the secondlifting step the left hand rack bar 67 and its cooperating pin 80 thusholes the lifting frame 15 in raised position. This second raising stepbrings the third pin 63 substanoccupied by the second pin which, aspointed out above, is substantially the same as the position occupied bythe first pin before the lifting platform was raised. Tl e handle 38 isagain raised to cause the lifting link to lower and to engage the thirdpin 63, whereupon the lifting handle 38 can be swung downwardly a thirdtime to raise the lifting platform through its third lifting step. Thepin 80 leaves the notch Z) on the rack bar 67 and takes a positionsubstantially midway between the notch 6 and the notch a, but at thistime the pin 81 on the other side of the truck will be moved from itshalf-way position between the notch (Z and the notch 0 into a positionwhere the pin 81 will be engaged by the notch c on the right hand rackbar 88. This holds the lifting frame in its elevated position for thethird lifting step. The fourth pin 63 is then brought to a positionwhere it can be engaged by the hooked end 55 of the lifting link whenthe lifting handle 38 is swung upwardly. The lifting handle 38 may thenbe swung downwardly again to raise the lifting platform to its fourthlifting step, which 'iovement causes the pin 81 to leave the notch c onthe rack bar 68 but at the same time causes the pin 80 on the left andside of the truck to be engaged by the notch a in the left hand rack bar67. Thus the lifting frame 15 is held in its uppermost raised position.

In this manner, the pins 80 and 81 act as pawls or fixed abutments onthe lifting frame, which pawls or fixed abutments cooperate with the tworack or ratchet bars and 68 carried by the main frame to hold thelifting frame in any one of its raised positions. @ne advantage flowingfrom the use of the two rack bars and. the staggered notch arrangementis that a number of steps can be provided for without necessitating rackor ratchet means havin too fine 'or too small teeth or notches, it b gunderstood that lift trucks of the present t, as are often subjected toquite heavy loads so that the means for holding the lifting plaform inraised position must be strong and sturdy and positive in its operation.

After the lifting frame has been raised to its upper position, thedetent l4 can be swung upwardly to release the same from the li tinglever 10, whereupon the handle 38 can be swung freely and used as atongue to pull and steer the truck from one place to another.

Mention has been made of the fact that during the lif' ing operationeach pin 63 occupies a position substantially the same as that occupiedby the next preceding pin, this operation being desirable in order thatthe hooked end can readily engage the next pin to raise the liftingplatform to the next lifting step. This means that the pins 63 must bearranged substantially on a curve having the same radius as the radiusof the are through which the lifting frame swings in its upward andforward raising movement, this radius being determined by the length ofthe links 21 and 25, but in order to bring the pins successively to thesame point relative to the main frame the center of curvature of the arcof the pins 83 is above the pins whereas the center of arc movement ofthe lifting frame 15 is below the points of connection between the linksand the lifting frame.

Since both the lifting link 50 and the pair rack bars 6? and 68,respectively.

in id igure 1, the

ofrack bars 67 and 68 always tend to move into engagement with theassociated pins un der the action of gravity, it necessary to raisethese parts out of engagement with the associated pins 63, S0 81 inorder to permit the lifting frame 15 to lower. Actually, as a practicalproposition, the lifting link 50 should be raised slightly in advance ofthe rack bars 67 and 68 so that the hooked end thereof will not becaught on any of the pins 63 as the lifting frame 15 lowers after therack bars 67 and 68 have been fully disengaged. As shown in figures 1and 2 the .neans l have provided to this end comprises a shaft 90journaled on the main frame by means of suitable ears or lugs 91 formedon the head 6. Near one end of this shaft 90 a foot pedal 98 isprovided. and is arranged to enteno forwardly to a point where it can beconveniently ooerated. The foot pedal 93 is fixed to the shaft 90 as byset screw or equivalent means. The shaft 90 carries t n'ee cams, t V0for the two rack bars 6? and 68 and a third cam for the lifting link 50which occupies internied te position between the two rack bars. shown,cams 95 and 96 are secured by set screws or the like to the shaft 90 andare positioned directly underneath the forwardmost ends of the Anintermediate cain member 9! s also secured to the shaft 90, as by a setscrew or the like, and this cam is positioned directly underneath thelifting link 50, see Figure 2, As best shown cam 9? which raises thelifting link 50 out. of engagement with the pins 63 is positioned on theshaft 90 slightly in ac vance of the other cams 95 and 96, the result ofthis arrangement being that when the foot pedal 93 is pressed downwardlythe first thing that occurs is that the lifting link 50 is raised, thencontinued downward movement of the foot pedal 3 swings the cams 95 and96 upwardly ag inst the uppermost ends of the rack bars 67 nd 66 androcks them out of engagement with the pins or pav 1 means 80 and 81 onthe lifting frame. N f 0 only one of the rack bars 67 and 68 isoperative at any one time to hold the lifting frame in raised position,it is necessary to hold both of hem a vay from the pins 80 and S1 orderto permit the lifting frame to lower the entire distance. Preferably, aspring 100 is biased between the top of the cross head 6 and the footpedal 93 to hold the same normally in upper position, thereby holdingthe cams of operative engagement 9:", 96 and 9'? o with the lifting link50 and the rack bars 67 and 68. The cross head 6 is also provit or witha detent 101 pivoted thereto by a pin 102 passing through the detent andcarried by suitable lugs 10% carried by the cross head. A spring 106serves to urge the detent 101 outwardly, the detent being provided withlimit means in the form of an adjustable set screw 108 which restrainsthe detent 101 from moving too far away from the cross head 6. Alaterally projecting abutment 110 is formed on the detent 101 and ispositioned to be engaged behind a hook portion 111 formed on the footpedal 93, as best shown in Figure 1. Thus, when the foot pedal 93 isfully depressed to raise the liftin link and the rack bars 67 and 68 out'of engagement with the lifting frame, the detent 101 will be cammedinwardly until the projection 110 rides behind the hook portion 111,whereupon the spring 106 urges the projecting abutment 110 to the bottomof the notch provided by the hook portion 111. In this way the hookpedal 93 is held in position to release the lifting link and the rackbars. When the lifting frame has fully lowered and it is desired toallow the lifting link 50 and the rack bars 6? and 68 to move intooperative engagement with the associated pins the operator steps on thedetent 101 and presses the same inwardly to release the projectingabutment 110 from the hook 111 on the foot pedal 93, whereupon thespring swings the foot pedal 93 upwardly and lowers the cams 95, 96 and97.

Preferably, the truck is provided with some form of check 115, such asahydraulic cylinder and piston arrangement, for the purpose ofcontrolling the descent of the lifting frame and preventing injury tothe truck and to the load carried thereby as would result if the liftingframe 15 were allowed to descend too rapidly. The check 115 may be ofany suitable construction. Preferably, the check 115 is arranged foroperation be tween the cross members 3 and 19, the former being carriedby the main frame and the latter being carried by the lifting frame.

Figures 3 to 5 illustrate a truck embodying the same lifting mechanismshown in Figures 1 and 2 but which is provided with a somewhat dilferentarrangement for holding the lifting frame 15 in raised position at theend of each lifting step. Certain generic features are present, however,in both forms, as will be apparent from the following detaileddescription. A pair of rack or ratchet bars 120 and 121 are pivoted tothe lifting frame by means of studs 123. The rack bars 120 and 121 aresuitably connected to swing together by means of a connecting bar 124suitably secured to each of the bars. [1 pin 126 is carried by each ofthe side bars 2 of the main frame 1 and these two pins serve as a pawlor abutment means with which suitably formed notches on the rack bars120 and 121 cooperate to hold the lifting frame in raised position. Inthis connection, the pins 126 serve the same purpose as the pins 80 and81 shown in Figures 1 and 2. The left hand rack bar 120 is shownin-detail in Figure 5. At. its forward end the bar 120 is provided witha boss 130 which is suitably apertured,

' reoted for the moment to the fact that as at 131, to receive the pivotstud 123 by which the .bar is pivoted to the main frame. The rearportion of the bar 120 is suitably formed to provide a plurality ofnotches, three in the present instant, being indicated by the referencecharacters e, f and 9. These notches are preferably formed in thematerial of the bar itself, the bar being cut away or suitably cast toprovide an intermediate portion 133 in which the notches e, f and g areformed. The bar 120 is also provided with a longitudinal passage orgroove 134 which extends along the notches e, f and g and serves as abypass along them. The top wall of the passage or groove 134 is given adownwarr; curvature, as indicated at 136, and the forward end of thegroove 134 is closed by means of a pivoted dog 137 equipped with aspring 133 which urges the lower end of the dog 137 against theintermediate portion 133 of the bar 120. Preferably, the pivoted detentor dog is mounted in a suitably formed transverse recess in the bar, thespring 138 being biased between one wall of the recess and the dog ordetent 137. The latter is pivoted to the bar 120 by means of a pivotstud 140. The bar 120 is also provided with a depending lug 141 which isapertured to receive the connecting bar 124 leading to the other rackbar 121 see Figure 4.

The operation of the rack bars 120 and 121 in holding the lifting framein raised position during the lifting operation will be described indetail later, attention being dionly three notches are provided by theholding bars 120 and 121 whereas the lifting frame is elevated in foursteps or stages, as de scribed above in connection with Figures 1 and 2.here in Figures 1 and 2 the lifting frame was held in its uppermostposition by one of the rack bars, the lift truck shown in Figures 3 andis provided with a separate latch 145 pivoted to the cross head 6 bymeans of a s-..aft 146 carriedby pair of ears or lugs 147 for e lintegral with the cross head e t 145 is provided with a hooked end 149which is adapted to engage over a 1 0 carried by a suitable shaft 151 aair of lugs 153 formed on a riv ted or otherwise secured to ie latch 145includes a lower pro ection 155 which receives a ct screw 156 whichserves 1 g s '11 position to engage the if 'ng frame when the latb:evated to its upper position.

holding ack bars 120 and 121 are o retain the lifting frame in thepositions, the latch 145 holding in its fourth or highest posidescribed.Referring now to k 3 5, it will be seen that when -e n-fting fra no isin its lowest position, the fixed pawl or pin 126 occupies a positiondirectly underneath the pivoted dog 137. When the lifting handle 38 isswung downwardly to raise the lifting platform through the first-liftingstage the rack bars 120 and 121 will be moved forwardly by the forwardand outward movement of the lifting frame, this movement causing theintermediate portion 133 on each of the rack bars to lie over the fixedpins 126. Once the pins clear the first or forward portion of theintermediate sections 133 the notches g engage the fixed pins 126 on themain frame and thus hold the lifting frame in its first position. Thelifting handle is then raised and again lowered which causes the hookedend of the lifting link to engage the second of the pins 63 and raisethe lifting platform another step to cause the second notch 7" formed oneach of the holding bars to engage the fixed pin 126. For the thirdstep, this operation is repeat-ed, the notch s c then engaging the fixedpins 126 to hold the lifting frame up. When the platform is again raisedthe rack bars 120 and 121 are then moved forward an amount sufficient tocause the pins 126 on the main frame to clear the rear ends of theintermediate portions 133. The rack bars 120 and 121 then pivotdownwardly about the pivot studs 123 until the upper edges 136 of therack bars rest 011 the pins 126. When in this position, the pins 126 arethen opposite the entrance to the groove or passage 134. When,therefore, the lifting platform is released by disengaging the latch 145from the roller 150 on the lifting frame, the latter lowers under theaction of gravity, being checked in its descent by the check 115, and asthe lifting frame lowers the latch bars 120 and 121 move rearwardly, thepins 126 entering the grooves 134. Near the end of their rearwardmovement due to the lowering of the lifting frame the rack bars havemoved rearwardly a sufficient amount to cause the dogs 137 to encounterthe fixed ends or studs 126. he last portion of the rearward move mentof the two rack bars causes the dogs 137 to be swung outwardly away fromthe end of the groove 134 and against the action of the retainingsprings 138. As soon as the dogs 137 are swung outwardly a sufiicientamount the pins 126 emergefrom the grooves 134, whereupon the pivoteddogs 137 swing back to the position shown in Figure 5 so that the pinsare prevented'from entering the grooves 134 until they pass over thenotches e, f and g in a manner to hold the lifting frame in elevatedposition during the first of the lifting steps. 7

For the reasons pointed out above in connection with Figures 1 and 2 itis necessary to raise the lifting link 50 out of engagement with thepins 63 when it is desired to lower the lifting frame 15. Figures 3 and4 illustrate the means for releasing the latch 145 and raising thelifting link 50 which is somewhat different in some respects than thereleasing means shown in Figures 1 and 2. In Figures 3 and 4, a footpedal 160 is shown as journaled upon the same shaft 1 16 upon which thelatch 1-15 is mounted. The foot pedal 160 includes a pair of lateralextensions 163 and 16 1, the former extending underneath a smallprojection 165 on one side of the latch 14:5 and the latter extension164 projecting to a point underneath the link 50. Thus, when the footpedal 160 is depressed the projection 163 raises the latch 1 15 and theprojection 1641 raises the lifting link 50. Preferably, theseprojections are so arranged that the lifting link is raised slightly inadvance of the latch 1 15. The foot pedal 160 is arranged to be held indepressed position by means of the detent 101 described in detail above.

Figures 6 and 7 illustrate a slightly different form of releasemechanism for disengaging the lifting link 50 from the pins 63. InFigure 6 the plates and 61 are shown as provided with rearward extension170 which carries a pivot pin 171 upon which a forwardly extendingcurved lever 172 is pivoted. This lever has a plurality of notches 173which are adapted to embrace the pins 63, and portions between thenotches 173 are adapted to be projected between the pins 63 for thepurpose of moving the end 55 of the lifting link 50 out of engagementwith the pins 63 when the lever 172 is swung to its upper position. Byvirtue of this construction no means for bodily lifting the lifting link50 is necessary, the lever 172 merely serving to fill the space betweenthe pins 63 to prevent the link 50 from becoming engaged with any ofthem as the lifting platform is being lowered.

In accordance with the generic feature of releasing the lifting link 50and the holding means from engagement with the lifting platform at thesame operation, Figure 6 illustrates one form of moving the lever 172upwardly at the same time the holding means for the lifting platform isreleased. The cross head 6 in Figure 7 is shown as provided with aplurality of rearwardly extending ears or lugs 175 in which is carried asuitable shaft 17 6. A foot pedal 180 is rigidly secured to the shaft 176, the latter also carrying a cam 181 formed with an abutment portion182. The lever 172 is adapted to be raised by means of a second lever185 having a lower and laterally extending portion 186 arranged toengage underneath the lever 172 and raise the same and an upperprojecting arm 187 cooperating with the cam 181. .Vh en the foot pedal189 is depressed the cam projection 182 abuts against the arm 187 andswings the lower end of the lever 185 upwardly against the lever 172,thereby causing the same to move the lifting link out of engagement withthe pins 63 and preventing the link 50 from reengaging therewith as longas the lever 172 is held in that position,

The holding means for retaining the platform in elevated posltion 1s notshown in,

Figure 6 because the releasing mechanism shown in Figure 6 is applicableto either the lift truck shown in Figure 1 or the lift truck shown inFigure 3. When used with the truck shown in Figure 1 the shaft 17 6carries the cams 95 and 96 for lifting the rack bars 67 and 68 out ofholding position, and when used with the truck shown in Figure 3, theshaft 176 carries the latch 1 15 loosely mounted thereon, the foot pedal180 then.

including a projection similar to the one shown in Figure 4 at 163 forthe purpose of operating the latch. The cam 181 is so timed that thelever 185 is raised slightly in advance of the release of the otherholding means, and the cam is so formed that further rotation of theshaft 176 is permitted without causing further movement of the lever185.

Figures 8 and 9 illustrate a further operat ing means for swinging thelever 172 upwardly to release the lifting link 50. As shown in Figure 8,the foot pedal 190 includes a depending arm 191 and is fixed to theshaft 176. A lever 193 is loosely journaled on the shaft 176 andincludes a lateral projection 194: which extends to a point underneaththe releasing lever 172, as in the case of the structure shown in Figure6. The lever 193 includes a projection 196 arranged opposite the arm191, and a spring 198 is biased between these two parts. As in the caseof Figure 6, the releasing mechanism shown in Figure 8 is adapted to beused in connection with either of the forms shown in Figures 1 and 3.The shaft 176 shown in Figure 8 may operate a latch 145, such as shownin Figure 3, or it may operate cams such as shown at 95 and 96 in Figure2. The foot pedal 190 with its arm 191 is arranged to first compress thespring 198 to raise the lever 172, whereupon further movement of thefoot pedal causes the disengagement of the hold ing means associatedwith the lifting truck, this further movement of the foot pedal havingno effect upon the lever 193 or the lever 172 other than to furthercompress the spring 198.

In both Figures 6 and 8, the foot pedal may be held in depressedposition by the pivoted detent 101.

While I have shown and described in detail the preferred structuralembodiment of the present invention, it will be understood that myinvention is not to be limited to the specific means shown and describedbut that, in fact, widely different means may be employed in thepractice of the broader aspects of my invention as defined by theappended claims.

What I claim, therefore, and desire to secure by Letters Patent is:

1. A lift truck comprising, in combination, main and lifting frames,lifting means carried by the main frame and operable to raise thelifting frame relatively thereto, and means for holding the liftingframe in a plurality of elevated positions comprising a pair of notchedrack bars, means pivoting said bars to the main frame, a pair of pins,one cooperating with one of said rack bars and the other cooperatingwith the other of said rack bars, and means securin the pins to thelifting frame.

2. A lift truck comprising, in combination, a wheel supported main frameincluding a transverse head and its forward end, a lifting frame pivotedto the main frame to swing upwardly, means carried by said head andcooperating with the lifting frame to raise the same, means for holdingthe lifting frame in raised position comprising a rack bar pivoted tothe main frame and extending forwardly and upwardly therefrom to a pointnear said head and a fixed abutment carried by the lifting frame andengaging the rack bar to hold the lifting frame in raised position, andmeans carried by said head for moving the rack bar out of engagementwith said fixed abutment to permit the lifting frame to lower.

3. A multi-lift truck comprising the combination with main and liftingframes of lifting means for raising the lifting frame relative to themain frame, said means comprising a vertically swin ing lever pivoted tothe main frame, a lifting link connected at its forward end with saidswinging lever and provided at its rear end with a hook portion, a pairof spaced plates fixedly secured to the lifting frame and positioned oneither side of said lifting link, and a plurality of pins carried bysaid plates in spaced apart relationship, the hook portion of saidlifting link cooperating with said pins to raise the lifting platform ina plurality of steps, means to hold the lifting platform in raisedposition, and means acting to release said holding means and also saidlifting link from engagement with said pins;

i. A lift truck comprising, in combina tion, main and lifting frames,lifting means for raising he lifting frame relative to the main frame,said means comprising a vertically swinging handle on the main frame, alifting link pivotally connected therewith and adapted to be oscillatedthereby from a lower position to an upper position, said lifting linl'having hook at'its lower end, and means carried by the lifting frame andadapted to be by the hooked end of said lifting link, said last nan edmeans being arranged in such a line that the hooked end engagessuccessive portions thereof from approximately the same lower positionduring the raising operation, and means arranged to hold the liftingframe in a plurality of elevated positions.

5. In a multi-lift truck, in combination, a wheeled main frame, alifting frame pivotally connected with the main frame to swing forwardlyand upwardly pair of studs carried by said plates and 6X tendinglaterally therefrom in opposite directions, a shaft fixed to the mainframe, a pair of rack bars journaled on said shaft and respectivelypositioned alongside of said plates, said rack bars being provided withnotches to cooperate respectively with said two studs, the notches onone bar being staggered with respect to the notches on the other barwhereby each bar and its associated stud are alternately operable toretain the lifting frame in elevated position, including pins carried bythe main frame and cooperating with the upper ends of said rack bars torelease said b s from engagement with said studs, and means associatedwith said last mentioned means for releasing the lifting link fromengagement with said pins, whereby the lifting frame is permitted tolower.

6. A multi-lift truck comprising main and lifting frames, meansconnecting the lifting frame to the main frame to swing forwardly andupwardly, lifting means for raising the lifting frame relative to themain frame, said means comprising a lifting link positioned substantialltangentially with respect to the arc of movement of the lifting frameand having hook lower end, and means serving as a rack fixed to thelifting frame and including portions substantially engageable with thehooked end of the lifting link, a rack bar journaled on the main frameand extending along said lifting link and also positioned approximatelytangentially with respect to the arc of movement'of the lifting frame, astud on the lifting frame and cooperating with the rack bar to hold thelifting frame in elevated position, and means including cooperating camsfor raising both the rack bar and the lifting link to disengage the sameto permit the lifting frame to lower.

7. A lift truck comprising, in combination, main and lifting frames,means to raise the lifting frame relative to the main frame including avertically swinging handle jonrnaled on the main frame, a llftlllg linkpivotally connector extending downwardly and rearwardly therefrom, saidlifting link being oscillatable by the lifting handle from a lowerposition to an upper position, said lifting link being formed with ahook portion adjacent its rear end, and a vertical plate secured to thelifting frame and having a number of pins projecting transverselythereof arranged to be successively'engaged by the hook end of saidlifting link, said pins being arranged relative thereto, a

with the lifting handle and ill) on a curve so that as the lifting frameis raised said pins successively occupy a position to be engaged by saidlifting link in its lower position, vertical swinging of the liftinghandle being operative to exert a pull on the lifting link whereby theplatform is raised and the next pin is brought to approximately the sameposition occupied by the preceding pin, ratchet means for holding thelifting frame in its various positions as it is being raised, saidratchet means comprising a rack bar pivoted to the main frame andextending forwardly and upwardly along said plate and a stud carried bysaid plate and engageable with the notches in said rock bar to hold thelifting frame in elevated position, means to release said lifting linkfrom said pins and said rack bar from said stud to permit the liftingframe to lower, said means comprising a transverse shaft journaled onthe main frame, means carried thereby for raising both the liftinglinkand said rack bar, a pedal secured to said shaft, and releasable meansfor holding the foot pedal in lower osition, and means to check thedescent of the lifting frame when released.

8. A multi-lift truck comprising, in combination, a main frame, alifting frame pivoted the to to swing forwardly and upwardly, a liftingmeans for raising the lifting frame relative to the main frame, saidlifting means comprising a vertically oscillatable lifting link iaving ahook portion at its lower end, a pair of vertical plates secured to thelifting frame and spaced apart to receive the lifting link therebetween,and a plurality of pins carried by said plates and spaced apart andarranged in a curve so that the hook portion of the lifting linksuccessively engages said pins to raise the lifting frame in a pluralityof steps, means to hold the lifting frame in elevated positioncomprising a bar pivoted to one of the frames and engageable with theother of said frames, and means to release said holding means to permitthe lifting frame to lower comprising a transverse shaft journaled onthe main frame, a forwardly extending foot pedal fixed to said shaft,and a cam fixed to said shaft and co operating with said holding means,and a second cam fixed to said shaft and cooperating with said liftinglink, said foot pedal being operable when depressed to swing the cams toraise both the lifting link and the holding bar out of engagement withthe lifting frame.

9. A lift truck comprising, in combination, main and lifting frames,lifting mechanism for raising the lifting frame relative to the mainframe, said mechanism comprising a lifting link having a hooked portionat its rear end and means secured to the lifting frame and acting as arack having portions successively engaged by the hooked end of thelifting link to raise the lifting frame in a plurality of steps,cooperating latch means on the main and lifting frames for holding thelifting frame in raised position, and means onthe main frame forreleasing both said latch and said lifting link from engagement with thelifting frame to permit the latter to lower.

10. A multi-lift truck comprising, in combination, main and liftingframes, a lifting handle pivoted to the main frame for vertical swinginga lifting link pivoted at one end to the lifting handle and having hookmeans at its other end, a pair of vertically positioned plates fixedlysecured to the lifting frame and positioned on either side of thelifting link, a plurality of spaced apart pins carried by said platesand successively engageable by said hook means to raise the liftingframe, a'rack bar pivoted to the lifting frame and including a pluralityof notches engageable with a fixed parton the main frame to hold thelifting frame in elevated position, said rack bar being provided withmeans cooperating with said fixed part on the main frame for by-passingthe notches on the rack bar whereby the latter is released from holdingengagement with the main frame, latch means for holding the liftingframe in position with said fixed part on the main frame disengaged fromthe notches on said rack bar, and means for releasing said latch andsaid lifting link to permit the lifting frame to lower.

11. In a multi-lift truck comprising main and lifting frames and meansfor raising the lifting frame relative to the main frame in a pluralityof steps, the combination of holding means for retaining the liftingframe in raised position during the step by step elevation thereof, saidlast named means in cluding a pair of rack bars pivoted to one of saidframes, a pair of fixed abutments on the other frame. each of said rackbars including a plurality of notches cooperating with one of said fixedabutments to hold the lifting frame in elevated position, there being aless number of notches than there are steps in the lifting operation tocompletely elevate the lifting frame, each of said rack bars alsoincluding a passage accommodating the associated fixed abutments andby-passing said notches, said passage being spaced relative .to saidnotches so that the associated fixed abutment enters the passage onlywhen the platform has been raised its full amount whereby to permit thelifting frame to lower, and means for preventing said fixed abutmentsfrom entering said passages except after the lifting frame has beenraised its full amount.

12. In a lift truck having main and lifting frames, the combination ofmeans including a pivoted lifting link engageable with the lifting frameto raise the same, latch means for holding the lift-ing frame inelevated position, and means for releasing both the latch and thelifting link from engagement with the lifting frame, said meanscomprising a foot pedal pivoted on the main frame and includinglaterally directed portions, one portion engaging said lifting link andthe other portion engaging said latch whereby said foot pedal may bedepressed to raise both the lifting link and the latch.

13. A lift truck comprising, in combination, main and lifting frames, avertically swinging handle pivoted to the main frame, a lifting linkpivoted at its forward end to said handle and having at its rear endhook means to engage the lifting platform to raise the same, a pair ofvertical spaced apart plates carried by the lifting frame and positioned on either side of the lifting link, a plurality of pins carriedby said plates and adapted to be successively engaged by said hookedmeans on the end of said lifting link, means to hold the lifting framein raised position, and means to release said last named means and alsoto release the lifting link from said pins, said means including a leverpivoted to said plates and portions movable into position between saidpins to prevent the hooked means from engaging therewith.

In witness whereof, I hereunto subscribe my name this 81st day of July,1931.

JOHN O. FERN STROM.

